68 research outputs found

    Comparison of the structures of the endothelin A receptor antagonists BQ123 and N-methyl leucine BQ123 with the crystal structure of the C-terminal tail of endothelin-1

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    AbstractThe functionally important regions of the cyclic pentapeptide endothelin A receptor antagonist BQ123 are shown to correlate with the structure of the C-terminal tail of endothelin-1, as found in the recently-determined X-ray crystal structure. Residues 18 and 21 of endothelin-1 are spatially juxtaposed such that they superpose extremely well withd-Asp andd-Trp of the antagonist, consistent with the residues on this surface of the endothelin helix being important for binding. This study provides new information on the three-dimensional nature of the endothelin A receptor binding site which may prove useful for rational drug design

    Conformational sampling by a general linearized embedding algorithm

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    Linearized embedding is a variant on the usual distance geometry methods for finding atomic Cartesian coordinates given constraints on interatomic distances. Instead of dealing primarily with the matrix of interatomic distances, linearized embedding concentrates on properties of the metric matrix, the matrix of inner products between pairs of vectors defining local coordinate systems within the molecule. We developed a pair of general computer programs that first convert a given arbitrary conformation of any covalent molecule from atomic Cartesian coordinates representation to internal local coordinate systems enforcing rigid valence geometry and then generate a random sampling of conformers in terms of atomic Cartesian coordinates that satisfy the rigid local geometry and a given list of interatomic distance constraints. We studied the sampling properties of this linearized embedding algorithm vs. a standard metric matrix embedding program, DGEOM, on cyclohexane, cycloheptane, and a cyclic pentapeptide. Linearized embedding always produces exactly correct bond lengths, bond angles, planarities, and chiralities; it runs at least two times faster per structure generated, and is successful as much as four times as often at refining these structures to full agreement with the constraints. It samples the full range of allowed conformations broadly, although not perfectly uniformly. Because local geometry is rigid, linearized embedding's sampling in terms of torsion angles is more restricted than that of DGEOM, but it finds in some instances conformations missed by DGEOM. © 1992 by John Wiley & Sons, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/38284/1/540131010_ftp.pd

    Strategies to inhibit tumour associated integrin receptors: rationale for dual and multi-antagonists

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    YesThe integrins are a family of 24 heterodimeric transmembrane cell surface receptors. Involvement in cell attachment to the extracellular matrix, motility, and proliferation identifies integrins as therapeutic targets in cancer and associated conditions; thrombosis, angiogenesis and osteoporosis. The most reported strategy for drug development is synthesis of an agent that is highly selective for a single integrin receptor. However, the ability of cancer cells to change their integrin repertoire in response to drug treatment renders this approach vulnerable to the development of resistance and paradoxical promotion of tumor growth. Here, we review progress towards development of antagonists targeting two or more members of the RGD-binding integrins, notably αvβ3, αvβ5, αvβ6, αvβ8, α5β1, and αIIbβ3, as anticancer therapeutics

    Outcome of the First wwPDB/CCDC/D3R Ligand Validation Workshop.

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    Crystallographic studies of ligands bound to biological macromolecules (proteins and nucleic acids) represent an important source of information concerning drug-target interactions, providing atomic level insights into the physical chemistry of complex formation between macromolecules and ligands. Of the more than 115,000 entries extant in the Protein Data Bank (PDB) archive, ∼75% include at least one non-polymeric ligand. Ligand geometrical and stereochemical quality, the suitability of ligand models for in silico drug discovery and design, and the goodness-of-fit of ligand models to electron-density maps vary widely across the archive. We describe the proceedings and conclusions from the first Worldwide PDB/Cambridge Crystallographic Data Center/Drug Design Data Resource (wwPDB/CCDC/D3R) Ligand Validation Workshop held at the Research Collaboratory for Structural Bioinformatics at Rutgers University on July 30-31, 2015. Experts in protein crystallography from academe and industry came together with non-profit and for-profit software providers for crystallography and with experts in computational chemistry and data archiving to discuss and make recommendations on best practices, as framed by a series of questions central to structural studies of macromolecule-ligand complexes. What data concerning bound ligands should be archived in the PDB? How should the ligands be best represented? How should structural models of macromolecule-ligand complexes be validated? What supplementary information should accompany publications of structural studies of biological macromolecules? Consensus recommendations on best practices developed in response to each of these questions are provided, together with some details regarding implementation. Important issues addressed but not resolved at the workshop are also enumerated.The workshop was supported by funding to RCSB PDB by the National Science Foundation (DBI 1338415); PDBe by the Wellcome Trust (104948); PDBj by JST-NBDC; BMRB by the National Institute of General Medical Sciences (GM109046); D3R by the National Institute of General Medical Sciences (GM111528); registration fees from industrial participants; and tax-deductible donations to the wwPDB Foundation by the Genentech Foundation and the Bristol-Myers Squibb Foundation.This is the final version of the article. It first appeared from Cell Press via https://doi.org//10.1016/j.str.2016.02.01

    Early Life Socialization as Impacting Neurotransmitter Concentration and Aggression

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    Mallory Peishoff ’22Majors: PsychologyFaculty Mentor: Dr. Victoria Templer, Psychology The study of aggression is a widely encompassing and highly applicable area of psychology, with a wide range of involved fields. To develop an understanding of the applications of aggression analysis, its causes must be established. The goal of this study was to develop an understanding of early life socialization as it affects behavioral expressions of aggression, as well as its impact on neurotransmitter concentration. Through a rat model, assigned groups of isolated and socialized rats were subjected to a resident-intruder paradigm. Screening for acts of aggression through the paradigm provided significant indicators that social deprivation at a young age causes an increase in aggression later in life. Wireless Instantaneous Neurotransmitter Concentration systems (WINCS) was applied to measure serotonin and dopamine concentration within subjects. Rats presented with a significantly decreased neurotransmitter concentration in comparison to control baseline results. Combining understanding of the two fronts, evidence suggests that social isolation in early life leads to heightened aggression and deficient neurotransmitter levels in adulthood

    COMPUTER-ASSISTED MECHANISTIC EVALUATION OF ORGANIC REACTIONS (CAMEO)

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    CAMEO, a mechanistically based computer program which predicts the products of organic reactions given starting materials and conditions has been enhanced in the area of base catalyzed and nucleophilic processes. The current status of the nucleophilic module is described including structure input, perception of reactive sites and mechanistic evaluation. In addition, the organizing principles used to ascertain the special reactivity of organosilicon compounds and the reactivity of aromatic, vinylic and acetylenic substrates towards nucleophiles are disscussed. The implementation of these areas of chemistry into the program is also described. Finally, the identification, stereochemical relationships and their effect on reactivity, particularly in intramolecular reactions, is considered
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